At one time flash mobs were and spontaneous public performances were novel and authentic. Then advertising and marketing people made promotional events that they tried to pass off as authentic encounters. Fortunately groups like Improve Everywhere, who describe themselves as A New York City based prank collective that causes scenes of chaos and joy in public places. The group's motto is "We Cause Scenes.", are still keeping it real. A group called MeTube also causes scenes of chaos and joy in public places. They're keeping it surreal: